This invention relates to the use of genetic engineering to produce desired heterologous polypeptides. (As used herein, "polypeptides" means any useful chain of amino acids, including proteins and peptides, and "heterologous" means a polypeptide not naturally produced by the host cell which produces the polypeptides.)
Bacillus strains have been used as hosts to produce heterologous polypeptides encoded on genetically engineered vectors. The use of a Gram positive Bacillus cell as host avoids some problems associated with expressing heterologous genes in Gram negative organisms such as E. coli; for example, problems associated with the production of endotoxins.
A number of Bacillus expression systems have been reported wherein heterologous proteins can be produced using a variety of cloned regulatory elements.
Hardy et al. (Nature, 1981, 293:481 and EP Application No. 82302157.1) expressed DNA sequences encoding the core antigen of hepatitis B virus and the major antigen of foot and mouth disease virus in Bacillus subtilis using the erythromycin resistance gene promoter on plasmid pBD9.
Williams et al. (Gene, 1981, 16:199) expressed the mouse dihydrofolate reductase gene in Bacillus subtilis using the vector pPL608, containing a phage SP02 promoter.
Ruppen et al. (in "Bacillus Molecular Genetics and Biotechnology Applications", eds. A. T. Garreson and J. A. Hoch, pp 423-432, Academic Press 1986) reported the use of the hybrid spac-1 promoter, a synthetic ribosome binding site, and the E. coli lpp gene terminater to produce recombinant human growth hormone in B. subtilis.